Tape cartridge

ABSTRACT

A tape cartridge has a reel having an external peripheral surface and a tape wound around the external peripheral surface of the reel. The peripheral surface has a shallow recess defined therein and extending in a peripheral direction of the reel. The recess is extended in a direction opposite a tape winding direction from a first point to a second point away from the first point. The recess is defined by an end wall extending inwardly from the first point to a third point away from the first point and a height substantially the same as a thickness of the tape. The recess also has a bottom wall extending peripherally from the third point to the second point and having a depth decreasing in proportion to a distance from the third point toward the second point. The portion of the tape is positioned in the recess so that the end wall abuts or opposes the end portion of the tape.

FIELD OF THE INVENTION

The present invention relates to a tape cartridge and, more particularly, to a tape cartridge which includes a cylindrical portion or hub having a cylindrical external peripheral surface and a tape wound around the hub.

BACKGROUND OF THE INVENTION

Conventionally, there exist two types of tape cartridges; double-reel cartridge and single-reel cartridge. Typically, in each cartridge the end of the tape placed on the cylindrical external surface of the hub is bonded thereto by a suitable means such as adhesive or a fixing arrangement.

When using adhesive, it is applied between the end of the tape and the peripheral surface of the hub. The tape has a certain thickness although small. Unavoidably, this results in a small radial level difference or step between the external peripheral surface of the hub and the external surface of the attached tape end. Disadvantageously, the step may cause a slight bent at a portion or respective portions of the tape overlying the step. The bent is permanently fixed in the tape over the long use thereof, which may result in unwanted contact detects of the reading and recording head against the bent portion or portions of the tape and the resultant data dropouts in the reading and recording operations.

To prevent the data dropouts, JP 2005-302113 A discloses a new tape cartridge in which the end portion of the tape to be initially wound around a couple of times on or over the step has a non-recording layer incapable of recording data therein, so that data is recorded in other tape portions following the non-recordable portions and free from any permanent bent. However, a high density recording tape may cause data dropouts only by slight step or bent, which requires an extended length of non-recordable portion and therefore decreases an amount of date to be recorded in the tape.

JP 07-235162 A discloses another cartridge in which one end of the tape is positioned in a recess formed in the external peripheral surface of the hub and then clamped by means of a claming member which is snug-fitted in the recess. This ensures a reliable fixing of the tape on the hub but may cause another level difference between the external peripheral surfaces of the hub and the clamping member. To eliminate the level difference, JP 07-235162 A proposes an improved arrangement in which a filling member, made of one or more strips, having a thickness substantially similar to the level difference is placed on the peripheral surface of the clamping member so as to eliminate the level difference. This arrangement, however, needs an additional operation to attach the filling member on the clamping member, which complicates the manufacturing process of the cartridge and thereby increases the product cost. Also, the tape is stretched by the winding and unwinding force to induce a displacement of the filling sheets beyond the step, which generates another step to cause the permanent bent in the tape.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide an improved tape cartridge which is capable of preventing the generation of the level difference or step and the resultant permanent bent in the tape, by means of an additional arrangement with a simple structure.

In order to achieve the foregoing object, the present invention provides a tape cartridge has a reel having an external peripheral surface and a tape wound around the external peripheral surface of the reel. The peripheral surface has a shallow recess defined therein and extending in a peripheral direction of the reel. The recess is extended in a direction opposite a tape winding direction from a first point to a second point away from the first point. The recess is defined by an end wall extending inwardly from the first point to a third point away from the first point and a height substantially the same as a thickness of the tape. The recess also has a bottom wall extending peripherally from the third point to the second point and having a depth decreasing in proportion to a distance from the third point toward the second point. The portion of the tape is positioned in the recess so that the end wall abuts or opposes the end portion of the tape.

According to the invention, there is no or substantially no level difference between the cylindrical peripheral surface of the hub and the end of the tape placed on the peripheral surface. Also, the other end of the recess smoothly lands on the peripheral surface of the hub. This eliminates the generation of bent in the tape which may otherwise cause unwanted data dropouts in the recording and/or reading operations.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is an enlarged, partial plan view of a tape cartridge according to an embodiment of the present invention;

FIG. 2 is a plan view of the tape cartridge according to an embodiment of the present invention;

FIG. 3A is a plan view of a hub of the tape cartridge;

FIG. 3B is an enlarged, partial plan view of the hub shown in FIG. 3A; and

FIG. 4 is a perspective view of the hub of the cartridge.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments are merely exemplary in nature and are in no way intended to limit the invention, its application, or uses.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, terms referring to specific directions (for example, “upper”, “lower”) may be used. It should be noted that these terms are used for the purpose of facilitating the understanding of the invention taken in conjunction with the drawings and meanings of these terms should not be construed as restricting the present invention.

FIGS. 1-4 illustrate an embodiment of the tape cartridge which is designed according to the present invention. Referring first to FIG. 2, the tape cartridge has a housing or container generally indicated by reference numeral 1. Typically, the housing 1 has a square or rectangular box-like configuration. Preferably, the housing 1 has a pair of upper and lower housing portions which are assembled to each other to form the housing 1.

In this embodiment, the tape cartridge 1, which is a single-reel cartridge, accommodates a reel generally indicated by reference numeral 2. The reel 2 is supported for rotation about an axis 20 (see FIG. 4) by a well-known bearing similar to that mounted in the conventional tape cartridge. Although the description will be made to the single-reel cartridge, the present invention can also be applied to the double-reel tape.

As shown in FIG. 4, the reel 2 has a cylindrical hub 5 and a pair of doughnut-like lower and upper flanges 6 and 7 secured on the opposite, lower and upper ends of the hub 5, respectively. Although the hub 5 is made of a hollow cylindrical member, it may be made of solid cylindrical member. Preferably, the lower flange 6 is molded integrally with the hub 5 and the upper flange 7 is fixed to the hub 2 by a suitable fixing means such as an ultrasonic welding.

A recording tape 3 made of magnetic film layer for recording digital data is wound around an external peripheral surface 9 or cylindrical surface of the hub 5. For example, the recording tape 3 has a thickness T of about eight micrometers (see FIG. 3).

One end or tailing end 11 of the tape 9 is attached on the peripheral surface 9 of the hub 5. The other end or leading end (not shown) of the tape 9 carries a leading block (also not shown). Although not shown, when not in use, the leading block is retained by a retainer fixedly mounted at an outlet opening formed on a side wall of the housing. Preferably, a reel-lock mechanism is provided so that, when not in use, the reel 2 is locked thereby to prevent the free rotation of the reel 2. Once the tape cartridge is mounted into an external device such: as recording/reading device, the reel-lock mechanism is unlocked by an associated mechanism of the external device and an associated catching and drawing mechanism catches and draws the leading block for unwinding the tape from the housing 1. The tape 3 from the housing 1 is conveyed into the external device in which it is transported through a loading path and then wound around a winding reel. The device has a reading/recording head provided adjacent the loading path so that the head makes frictional contacts with the transporting tape to read data therefrom and/or record data therein.

Referring to FIGS. 3A and 3B, the outer peripheral surface 9 of the hub 5 has a shallow recess 10 extending substantially the entire widthwise length of the outer peripheral surface 9 and also extending in the peripheral direction of the hub to a certain length. In detail, with respect to a direction opposite to the winding direction 30 of the reel 2, the recess 10 is extended from a first peripheral surface point 31 to a second peripheral surface point 32 on the peripheral surface 9 of the hub 5. An inner surface of the recess 10 defines an end wall 33 and a bottom wall 34. The end wall 33 is extended radially inwardly from the first point 31 to a third point indicated at 35. The bottom wall 34 is extended from the third point 35 to the second point 32. Although the recess 10 is exaggerated in the drawings for the better understanding of the invention, a height L of the end wall 33 is very small and substantially the same as the thickness T of the tape 3.

In FIG. 3B, the imaginary line or long and short dotted line 9 a indicates a line connecting the first and second points 31 and 32 with the same radius of curvature as the peripheral surface 9 of the hub 5. As shown in the drawing, a depth of the recess 10, i.e., a distance between the line 9 a and the bottom wall 34, decreases in proportion to a distance from the first point 31 toward the second point 32. In this embodiment, the bottom wall 34 has a radius of curvature substantially the same as that of peripheral wall 9. Preferably, a portion 35 a of the bottom wall 35, in the very vicinity of the second point 32, defines a tangential line substantially identical to that defined at the second point 32, so that the bottom wall 35 smoothly lands on the peripheral surface 9.

With the arrangement, the tailing end 11 of the tape 3 is placed in the recess 10 and the end wall 11 a of the tape 3 abuts or opposes the end wall 33 of the recess 10. The tailing end 11 of the tape 3 may be made of a transparent film free from magnetic recording layer. Although the entire peripheral length of the bottom wall 34 is formed by the curved surface in the previous embodiment, it may be formed by a first straight wall portion starting from the third point 35 and a subsequent, second curved wall reaching the second point 32.

Preferably, the tailing end 11 of the tape 3 is fixed to the bottom wall 34 by means of a suitable adhesive. Before bonding, the adhesive may be applied on the bottom surface 10 or the opposing surface portion of the tape 3 to be placed on the bottom wall 34.

As described above, since the height of the end wall 33 is substantially the same as the thickness of the tape 3, the outer surface of the tailing end 11 of the tape 3 lies in flush with the adjacent unrecessed peripheral surface portion 9 b of the hub 5 (see FIG. 3B), without forming any step or level difference therebetween. Also, since the end portion of the bottom wall 34, away from the end wall 33, smoothly coincides with and lands on the peripheral surface 9 at the second point 32, no or substantially no bent will be formed at portions of the tape lying on the second portion 32. This ensures that no bent occurs at respective portions of the tape overlying the peripheral ends of the recess 10.

Although it is most preferable that the height L of the end wall 33 is the same as the thickness T of the tape 3, the height L may have a certain size tolerance of, for example, ±0.5% of the tape thickness T. This amount of size tolerance may not induce a harmful or detrimental affect in reading and/recording data on the tape, such as data dropout.

The end wall 33 may be inclined with respect to the radial direction of the hub. In this instance, it is preferable that the end wall 33 of the tape 3 is inclined in compatible with the associated inclined leading wall to prevent a generation of gap between the opposing ends.

Also, the recess 10 may be formed integrally at the molding of the hub 5 or formed by cutting the molded hub 5.

Further, although the bottom corner connecting the end wall 33 and the bottom wall 34 is illustrated to have substantially a right angle, it may be rounded. In this instance, it is preferable that the tailing end 11 a of the tape 3 is stayed slightly away from the end wall 33 beyond the rounded corner surface. The gap between the tailing end 11 and the opposing end wall 33 is still small, so that no bent would occur in the tape portion overlying the gap.

Furthermore, although the end portion of the tape is bonded to the bottom wall 34, it is not necessary to be fixed thereto. In this instance, the external device should be controlled to leave a couple of tape windings on the hub at the completion of the unwinding of the tape.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention. 

1. A tape cartridge, comprising: a reel having an external peripheral surface; and a tape wound around the external peripheral surface of the reel; the peripheral surface having a shallow recess defined therein and extending in a peripheral direction of the reel, the recess being extended in a direction opposite a tape winding direction from a first point to a second point away from the first point, the recess being defined by an end wall extending inwardly from the first point to a third point away from the first point and a height substantially the same as a thickness of the tape and a bottom wall extending peripherally from the third point to the second point and having a depth decreasing in proportion to a distance from the third point toward the second point; one end portion of the tape being positioned in the recess so that the end wall abuts or opposes the end portion of the tape.
 2. The tape cartridge of claim 1, wherein the bottom wall has a radius of curvature substantially the same as that of the peripheral surface.
 3. The tape cartridge of claim 1, wherein the bottom surface has a straight wall portion formed adjacent the third point and a curved wall portion adjacent the second point and having a radius of curvature substantially the same as that of the peripheral surface.
 4. The tape cartridge of claim 1, wherein a height of the end wall has a size tolerance of about ±0.5% of the tape thickness T. 